The cohort model by Keller et al. [29], which found screening followed by selective treatment to be cost-effective, was the only study to model prostate cancer according to the D’amico classification of low risk (G ≤ 6, PSA ≤ 10,≤T1a), intermediate (G ≤ 7, PSA ≤ 20, ≤T2b), high (G > 7,PSA > 20,>T2b), and advanced cancer. This evidence concerns the gene KLK3 and cancer.